The triumph on bestseller lists of the novel Suite Française restores one's faith in popular taste. It is very moving to see Irène Némirovsky's near-masterpiece achieve success more than 60 years after its Jewish author perished in Auschwitz. Her tale of occupied France in 1941 is all the more chilling because it is written with such generosity of spirit, not only towards the French, but even the Germans who were to murder her.

Many British people who read narratives of that period find it hard to avoid complacency. The French quit, Britain fought on. Most of their people collaborated with the Nazis; French policemen dispatched Némirovsky to a death camp. It is not a pretty story, which explains why France, almost alone of the combatant nations, has never published an official history of that experience. Even in the 21st century, it would be impossible to achieve a consensus about the truth.

Suite Française has prompted renewed debate about societies' conduct under occupation. Hearing a recent conversation about collaboration, I made myself unpopular by suggesting that, if Britain had succumbed to Nazi rule, our own people would have behaved pretty much as the French did. Anthony Eden is seldom quoted with respect these days. Yet the former foreign secretary made an impressive contribution to Marcel Ophüls' great film on wartime France, Le Chagrin et la Pitié. He said, in impeccable French: "It would be impertinent for any country that has never suffered occupation to pass judgment on one that did." Here was wisdom.

It is extraordinarily difficult to resist tyranny ruthlessly enforced, especially in a densely populated country with little wilderness. In order to eat and provide for one's family, it is necessary to earn money. All commerce and industry must be conducted according to the will of the occupiers. A man who owns a business will find that he has no business, his employees no work, if he does not accept dictation. Members of a family that owns a house are liable to find it burnt about their ears if they commit, or are even deemed to have acquiesced in, acts of resistance. Some people may feel brave enough to accept such consequences for themselves, but would they inflict them on their children?

In the 1930s many prominent British aristocrats, like their French counterparts, developed a morbid terror of the left. This caused them to be less frightened of the Nazis, who did not threaten their material interests, than of communist revolutionaries, who did. It is a bleak truth, highlighted by French experience, that the greater one's possessions, the more painful it is to risk their loss. The French aristocracy collaborated almost wholesale. The names of honourable exceptions are remembered because they were so few.

Their British counterparts would probably have done likewise. Great proprietors believe their highest duty is to transfer inheritances safely to the next generation. Many British grandees fought bravely in the second world war but would, I think, have bowed to the Germans under occupation rather than forfeit the likes of Chatsworth or Blenheim. "We hate the Germans," they would have said, "but we must face the fact that they are masters now."

Most of France's "haves" collaborated not willingly, but in the face of perceived necessity. The bourgeois classes allowed their view to be determined by law-and-order arguments, which possess even greater force in war than in peace. Sabotage provoked murderous reprisals upon the innocent. Surely, people said, it is in the interests of the community that we behave in such a way as to be spared killings and confiscations, when daily existence is harsh enough already.

Resistance, confined to a small minority until 1944, was dominated by what middle-class people would categorise as "the awkward squad": teachers and unionists (many of them leftists), young mavericks, communist activists, journalists, peasants: in short, little people.

All this, I think, would have applied equally in a German-occupied Britain. A harder question to answer is whether British people would have dispatched their own Jews to death, as did the French. There was considerable anti-semitism in prewar Britain; it is sometimes remarked that "the biggest favour Hitler did the British upper classes was to make anti-semitism cease to be respectable". British anti-Jewish sentiment, however, was less virulent than that of the French. It is pleasant to suppose that a fundamental decency might have rendered ordinary people unwilling to denounce their Jewish neighbours, even had a British collaborationist government urged them to do so.

The Gestapo noted with relish that each morning the letter box of its Paris HQ in Avenue Foch was jammed with anonymous letters from citizens accusing each other of black-marketeering or resistance activity. Most British agents captured during the occupation were betrayed by Frenchmen. Would the British have likewise turned on each other?

Humility of the kind displayed by Eden is the only sensible course in judging another nation's behaviour under circumstances that we have been spared. Némirovsky's great novel paints a portrait of a society that did not conduct itself with conspicuous courage or honour. I am doubtful, however, that we would have done much better.